Some thoughts on the FWB124 trigger

[rodrigo571]

Hi!!
This is material I posted many years ago in an older forum...
Maybe this can be useful for some folks.
Regards,
Rodrigo.
-----------------------------


I bought a FWB124 in decent/good condition, some months ago, serial number around 51,000. It was doing 9.5 - 10 fpe so I left it in the safe, waiting for a rebuild with JM's parts. The time has finally come and, prior to disassembly, I did some shots again, to test the "feel" of the trigger.

Well, this is just my gun and just my case -- so this post is not intended to be "Universal Truth" or to represent everybody's gun (I'm totally ignorant about versions of this gun)....

I think the trigger is pretty nice, it has two clear stages and the trigger pull is reasonable. It also brakes clean/predictable. The trigger blade returns properly to the rest position if shot is aborted, that is, it does not have the problem others have reported. I could say this trigger is almost as nice as the one in a Diana 27 - a decent sporting trigger !!

Now, lets disassembly the trigger. Before disassembly, this is how the trigger group looks like. Upper view:

View from down:

Now, begin removing the forward pin:

Once the pin is out, the trigger blade, together with the main sear and the little spring between both, are released:

They can be retrieved from up:

A picture of these 3 parts:

Now continue removing the rear pin:

Once the pin is out, the other sear (which I will just call the "auxiliary sear" here) is released and falls out by itself:

For reassembly, the advice "proceed in reverse mode..." applies as usual. Additional tips: first, place the auxiliary sear and put the rear pin, help yourself with a set of pliers for alignment:

Then place the trigger blade (with the little spring inserted into it) inside the block - only the blade, not the main sear. If done correctly, the auxiliary sear shall appear on the upper side of the trigger blade. Align the blade so it looks properly seated inside the block. Side view:

Upper view:

Now slide the main sear inside the block, from up. The auxiliary sear must be centered on its pin prior to this:

Finally, align blade and main sear, moving them as little as possible, and try to make a visible aperture on the forward pin hole. Can you see this aperture?

Most probably this aperture wont be "precise" enough to allow successful insertion of the pin. So, take a little screwdriver -or whatever similar tool - and use it to insert into the hole and align the parts:

Then, with the screwdriver still inserted, proceed to insert the pin, from the opposite side.

As you can see, this is a very simple trigger, consisting of only 3 parts and 2 springs. It makes me smile to imagine those highest-qualified FWB engineers, receiving an infamous order: "build a CHEAP trigger!!", and executing it, feeling nasty/heretic about it, having nightmares, etc. LOL.

TO BE CONTINUED...

 

[rodrigo571]

Now lets see the function of the trigger.

The trigger group, assembled outside the block, using the pins partially inserted on the block:

Several views at different angles:

The trigger needs pressure on the auxiliary sear to work properly (pressure downwards). I mean, once cocked, this pressure is what keeps "everything in place". That is exactly the function of the spring that goes under the safety tab:

Now the sear is cocked:

Note that if you increase the pressure, the sear engagement increases:

Now the firing cycle. First, the first stage - the screw is not touching the auxiliary sear:

Then, the second stage - the screw touches the auxiliary sear:

An finally, the trigger fires:

I found disconcerting the fact that the amount of sear that engages depends on the force is applied by the upper spring. More force means more engagement, less force means less engagement and, at a certain point, if force is too small, the trigger will suddenly fire !!

I don't know if this is a common feature among airgun triggers, but probably this is something that can be dangerous. Certainly, a good reason to have a healthy spring there, and not to mess with it, as has been suggested by some tuners...

I think this is probably the same reason why so many people complain about "strange" trigger behaviors on their 124s - all different, on the same gun. The reason -I think- is because the behavior of this trigger depends too much on how "strong" this spring is: 1000 "different" springs lead to 1000 "different" trigger feelings, on a same gun.

One thing that I could not determine is how the trigger is cocked. I suppose, but am not sure, that it is done by the piston stem, pushing the main sear and forcing it to engage with the auxiliary sear.

As for my case, I will install one of JM's custom trigger guards and will leave those springs alone. Trigger feeling was nice before, and I hope to maintain that feeling after rebuild. For no reason I will try to reduce the trigger weight by messing with those "devilish springs"....

-------------------------------

 

[fishing43]

Hi!!
This is material I posted many years ago in an older forum...
Maybe this can be useful for some folks.
Regards,
Rodrigo.
-----------------------------


I bought a FWB124 in decent/good condition, some months ago, serial number around 51,000. It was doing 9.5 - 10 fpe so I left it in the safe, waiting for a rebuild with JM's parts. The time has finally come and, prior to disassembly, I did some shots again, to test the "feel" of the trigger.

Well, this is just my gun and just my case -- so this post is not intended to be "Universal Truth" or to represent everybody's gun (I'm totally ignorant about versions of this gun)....

I think the trigger is pretty nice, it has two clear stages and the trigger pull is reasonable. It also brakes clean/predictable. The trigger blade returns properly to the rest position if shot is aborted, that is, it does not have the problem others have reported. I could say this trigger is almost as nice as the one in a Diana 27 - a decent sporting trigger !!

Now, lets disassembly the trigger. Before disassembly, this is how the trigger group looks like. Upper view:

View attachment 359582

View from down:

View attachment 359581

Now, begin removing the forward pin:

View attachment 359583

Once the pin is out, the trigger blade, together with the main sear and the little spring between both, are released:

View attachment 359580

They can be retrieved from up:

View attachment 359584

A picture of these 3 parts:

View attachment 359587

Now continue removing the rear pin:

View attachment 359590

Once the pin is out, the other sear (which I will just call the "auxiliary sear" here) is released and falls out by itself:

View attachment 359585

For reassembly, the advice "proceed in reverse mode..." applies as usual. Additional tips: first, place the auxiliary sear and put the rear pin, help yourself with a set of pliers for alignment:

View attachment 359586

Then place the trigger blade (with the little spring inserted into it) inside the block - only the blade, not the main sear. If done correctly, the auxiliary sear shall appear on the upper side of the trigger blade. Align the blade so it looks properly seated inside the block. Side view:

View attachment 359589

Upper view:

View attachment 359588

Now slide the main sear inside the block, from up. The auxiliary sear must be centered on its pin prior to this:

View attachment 359593

View attachment 359591

Finally, align blade and main sear, moving them as little as possible, and try to make a visible aperture on the forward pin hole. Can you see this aperture?

View attachment 359592

Most probably this aperture wont be "precise" enough to allow successful insertion of the pin. So, take a little screwdriver -or whatever similar tool - and use it to insert into the hole and align the parts:

View attachment 359595

Then, with the screwdriver still inserted, proceed to insert the pin, from the opposite side.

As you can see, this is a very simple trigger, consisting of only 3 parts and 2 springs. It makes me smile to imagine those highest-qualified FWB engineers, receiving an infamous order: "build a CHEAP trigger!!", and executing it, feeling nasty/heretic about it, having nightmares, etc. LOL.

TO BE CONTINUED...

Thank you for the advice

 

[JDR]

Wish I could get my FWB 124D trigger pull less than 1lb. Fooled with it for 15 minutes after watching a video on adjusting the trigger. 1.5 lb was the best I could do.

 

[rodrigo571]

The way the trigger is designed, it seems you cannot simply adjust its weight. It seems the force is made against the spring, with no adjustments possible. Maybe a lighter spring? But if you put a lighter spring, then the amount of total sear engagement (1st + 2nd stage) is reduced, which could have unexpected effects.

I felt the trigger in my gun was pretty decent the way it was when I bought it. So, I didn’t try to adjust it... I was lucky!!!

PS: 1.5 pounds sounds OK.